The primary purpose of this Phase I/II trial is to establish the safety of administration of the Y-90eled Immu-LL2 antibody and to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT). The DLT is almost always related to bone marrow toxicity, and to this end frequent monitoring of blood counts is performed in the period following administration of the therapeutic dose. In addition, the study will also evaluate by CT and FDG-PET the response of tumor to therapeutic doses of the antibodies. This is not the primary objective of the trial, but based on earlier observations of tumor regression with very small doses of radioactivity, it is a likely event. The possible development of antibody response to the administered antibodies will be monitored as well. The data obtained from these preliminaary phases will be used to further design trials to evaluate the safety and efficacy of the radiolabeled antibodies.